Tube socket



' June 15, 1959 4A. c. GREGsoN ETAL 2,891,231

TUBE SOCKET Filed Feb. 28,1958

INVENTORS, v ALVERO C. GREGSON 8 BY MART/N RENN/E.

MMM-M A T TOR/VE Y arent 2,891,231 Patented June iS, 1959 TUBE SOCKET Alvero C. Gregson, Garden City, and Rennie, I-Iicksvlle, N.Y., assignors to the United States ot America as represented by the Secretary of the Army Application February 28, `1958, Serial No. 718,389

1 Claim. (Cl. 339-93) This invention relates to improvements in electron tube sockets and more particularly to a floating mounting therefor to render it self-aligning.

It is Well known that in electronic apparatus designed to operate at frequencies of the order of one-hundred megacycles or more, the connections between components in the circuits should be as short as possible. This is particularly true of components connected to the amplifying tubes. One means by `which these short connections to the tubes may be effected is by eliminating the tube socket, which is standard with most low power tubes, and connecting the chassis ground directly to the pins at a point near where they are sealed to the tube. There is no diculty in making these connections to low power tubes Wherethe currents are comparatively small. However,` for high power ampliier tubes, such as for instance the present day transmitting tubes type 4X15-A or 4X250, it is necessary that the connecting devices be exible in order that strains set up by the heating action of the large currents will not crack the glass seal of the tube. Another important consideration in these transmitting tubes is that the pin contacts to which the cathode is connected be short to provide the required low cathode lead inductance for high frequency operation.

With the foregoing in mind, it is an object of this invention to provide an improved selfealigning and oating tube socket.

A further object of this invention is to provide a socket with short low inductance leads and having mechanical flexibility.

Accordingly, it is a feature of the present invention to adapt a conventional tube holder with supporting means permitting the connection of at least some of the pins of a tube to a circuit with short sliding contacts, and still allow the pins to be free for movement in response to heating.

For a more detailed description of the invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawing, wherein:

Fig. 1 is an enlarged bottom plan view of the socket;

Fig. 2 is a cross-section along line 2--2 in Fig. l; and

Fig. 3 is a perspective view of a metallic ring, on a reduced scale, forming part of the invention.

In Fig. 2 the invention is illustrated in its adaptation to a conventional molded tube holder constructed of insulating material, and preferably provided with a plurality of holes in the top; as may be seen in Fig. 2 one of such holes 12 is shown in the broken away portion of the drawing. These holes will, of course, be of the proper size and arrangement to accommodate the pins of the tube or other device for which the holder is designed. A conventional transmitting tube, the base 14 of which is shown in dotted lines, is inserted in the holder 10. For clarity, one pin 16 of the tube base 14 is shown in contact with its metallic sleeve 18, one of a plurality of sleeves which extend through the holder 10 to terminate in conventional conducting lugs 20, 22, 24 and 26, to which the necessary connections may be attached for connecting the tube into a circuit. While only the ends of four lugs are shown in Fig. l, the holder may have additional lugs for the connection of other circuit wires.

A metallic saddle 28 is attached to the holder 10 by a ilexible retaining ring 30, said saddle lbeing provided with holes 32 and 34 for mounting the holder to metal plate support 36 with fasteners such as rivets 38 and 44B. Circular metallic spacers 42 and 44 are arranged concentrically within saddle mounting holes 32 and 34 respectively. The external diameter of the spacers is smaller than the diameter of said holes to permit circumferential and radial movement of the saddle with respect to the spacers. In addition, these spacers prevent any clamping of the saddle that might occur upon fastening at this particular spot to the metal plate 36.

Mounted in contact with saddle 28 is a metallic ring 46, best seen in Fig. 3, having opposite at surfaces. The flat surface of ring 46, next to saddle 28, is provided with two oppositely disposed longitudinal channels 4S and 50. These channels provide a recess for the end portions of saddle 28 and permit the ends of the saddle to be mounted therein. Since the channels are deeper than the thickness of the end portions of saddle 28, the latter can move axially in said channels. The end portions are also narrower than the channels so that the saddle can also move laterally in said channels. An apertured metallic disc 52 is securely held in contact with the bottom surface of ring 46. As shown in Fig. 2, the aperture 53 of disc 52 is larger than the bottom diameter of holder 10, and the conducting lugs 20, 22, 24 and 26 projecting from the latter, extend through said aperture. Disc 52 is a cathode terminal disc to which lugs 2h to 26, which are all cathode lugs, are to be connected. For this purpose, flat strips 54, 56, 58 and 60, constructed of resilient sheet metal cut and shaped in the desired manner, are provided with slots at one end wherein the lugs 20, 22, 24 and 26 tit respectively. In assembly, the lugs are inserted into the slotted ends of their respective strips and soldered, while the other ends of the strips make a sliding contact with disc 52. Associated with the strips 54, 56, 58 and 60 are spring fingers 62, 64, 66 and 63 which are provided to form with disc 52 a number of pressure gripping bearings for the strips. Each of the metallic spring ngers 62, 64, 66 and 68 is formed with a bend at a point intermediate its ends, so that they slidingly engage the strips 54, 56, 5S and 60 at points further inward from the free ends of same, and add a desired degree of yielding support to the tube holder 1t). it necessary, excess portions of lugs 2G to 26, which may extend beyond the point where they are soldered to their respective strips should be cut olf to permit a maximum amount of lateral movement of the holder 10, and thus prevent contact with the extreme turned down ends of spring ngers 62, 64, 66 and 68 when the holder shifts.

The arrangement of the spring ngers is such that the strips frictionally engage their respective spring ngers to form a good electrical connection therebetween. The other ends of the spring lingers are held securely between two similar metallic ring spacers 70 and 72 which are employed and disposed as shown in Fig. 2, one on each side of the fingers.

The rivets 38 and 40 secure together ring spacers 72 and 70, spring fingers 66 and 62 respectively, disc 52, ring 46, saddle 28 and spacers 42 and 44, respectively, and fasten these members to the metal support 36. Two other rivets 74 and 76 secure together ring spacers 72 and 7d, spring fingers 68 and 64, respectively, disc 52 and ring 46.

The construction as described and shown alfords a heating mounting and permits the holder 10 to move laterally and axially with respect to the metal plate support 36 and the rivets 38 and 40, and compensate for structural or manufacturing variations in the tube pin locations and also for the differences in the coeicient lof expansion ofthe metlplte 36 and the 'glass seal 'of the tube hase l'llvvhich )would set up strains qthat might easily crack 'the tube if nthe tube holder vWere held in iiired position. l n

In operation, when an electron tube base" 14 'or yother device having a male portion or Vplug is inserted into the holder Il), the strips and their associated spring fingers first give slightly under the dovvnvvardpressure feirerted, but then furnish a practically rigid backing, in the axial direction, when the saddle /28Vco`mes t'o rest in the channels 48 and V50 provided in the ring 46. Should there be any;misalignment between any of the strips and 'the spring'ngers, these elements vvill yield accordingly to permit adequate shifting of the same. nSince each of the four spring llingers is thus enabledy -vto move bodilytoalign itself With the respective complementary strip, each spring nger is able vto contributeits share of the current 'flowing through the cathode of Athe tube.

While there -has been described whatV is at present -considered a .preferred embodiment of 'the invention,- it will be obvious Ito those skilled in the art that various changes Y and modifications may be made therein without departsite 'flat surfaces and provided with diametrically opposed channels in one of said surfaces, a metallic cathode teriil di's 'Having Cifl p'fl "d'i'cll'tt With the opposite surface of said ring, a tube holder of insulating material adapted to receive the pins of said tube and having electrical conducting lugs connected to the cathode pins of said tube extending from said tube holder therefrom through said aperture, a metallic saddle encompassing said holder and provided with a hole near each end thereof, a circular metal spacer having a central hole for mounting purposes positioned in each hole of said saddle to permit a limited lateral movement `of said saddle With respect yto vsaid spacer-"s, 'theends of said saddle being mounted in said channels and Vaxially -and laterally movable therein, a metal plate having an opening therein for receiving said holder, 'said metal plate being adapted to limit the axial movement of said saddle in said channel, `a plurality of metal strips permanently axed at each of their respective ends to `said lugs and hav-ing the other respective ends vcontacting said disc, a like plurality of metallic iingers slidably engaged v'fith said respective metal stripsat each of their 'respective ends, means for VaiXiHg said spring lingers Aat vvtheir other respective ends 'to-'said disc, and conductive means Which maintain said plate in spaced relationship with said di'sc andvwhich maintain contact between said spacers, said saddle, said ring, said spring ng'ers and 4said .means J"for aixing Vsaid spring'iingers' to said disc.

References Cima fthe are offrhis 'parent UNITED STATES PATNTS .1. sie *e 

